Production of Fish Silages from Fish Entrails and Its Nutritional Evaluation

Abstract

The study was undertaken to investigate fish entrails (heads, bones, viscera, fins) suitability as raw materials for fish silage production for the fish feed supplement. Two types of fish silages were prepared using pure culture of Lactobacillus as lactic fermentation starter and formic acid as acid fermenter. Lactobacilli was isolated and identified for the preparation of fermentation starter from fresh milk. The starter bacteria and molasses were added to minced raw materials in three different compositions to produce three fermented silages and 3% formic acid was used for acid silage production. Biochemical changes were monitored continuously during the fermentation of the silages. Non-protein nitrogen concentration increased from an initial value of 19.56% to 42%. The proximate composition of the final products after 80 days of fermentation on dry matter basis showed that acid silage contained higher crude protein (31.25±0.75%) than fermented silages (21±0.54% - 28±1.11%). Crude lipid content didn’t show any significant differences among silages prepared (P>0.5). Most of the essential amino acids were present in fairly good concentration in all the silages which are comparable to those of the FAO/WHO requirement. Protein content and the amino acid profile of the silages suggest that it should be possible to partially replace with fish meal in feeds for fish and animal.